Unpacking Online Asynchronous Collaboration in mathematics teacher education

We report on one aspect of an extended research and development project that was conducted to support teachers?? development of mathematical knowledge for teaching (MKT) algebra through participation and authentic engagement in online collaborative mathematical problem solving. This article expands on our recent work, which has succeeded in developing a model for supporting teachers?? mathematical development at a distance that has shown great promise for supporting significant gains in teachers?? MKT. Specifically, this ex-post-facto analysis consisted of qualitative, micro-level analysis of the content of teachers?? activity and generated artifacts and helps us understand how the various collaborative activities (specific combinations of interaction, instructor support and feedback, and technology) supported and/or constrained the development of MKT algebra in an online environment.